This invention relates to an improved ignition system for oil burners and to a coil/core construction used in the ignition system.
In particular, this invention relates to a coil/core construction in which the primary coil, secondary coil and a feedback coil are all mounted in axially coextensive and magnetically coupled relation radially about a straight ferrite core.
U.S. Pat. Nos. 4,403,943 and 4,412,269 disclose oil burner ignition systems. The former patent discloses a device for oil burners which includes an electrically controlled valve for feeding fuel to the burner. An oscillating circuit connected to a transistor serves to generate the high frequency voltage which is stepped-up by a transformer to generate the ignition spark. The transformer includes a primary coil, secondary coil and two other coils for controlling the operation of the transistor.
The physical arrangement of the transformer is depicted in the U.S. Pat. No. 4,412,269 wherein the secondary coil is wound about a bobbin and fitted about one end portion of an elongated ferrite core. The primary coil 65 is wound on a separate bobbin or reel 64 having a sleeve 66. The core is fitted into the sleeve and magnetically couples the secondary coil and primary which are disposed about different longitudinal portions of the core.
While the above-referenced patents disclose ignition devices for liquid fuel burners which are satisfactory in operation, it is the principal object of this invention to provide an improved ignition of the same general type.
It is another object of this invention to provide an ignition system of the above-type which is more economical to manufacture, more compact in size and has a significantly longer operating life because of its coil/core construction.
It is a further object of this invention to provide an oil burner ignition system which has fewer parts and is compatible with 110 volt, 60 cycle energy source or other conventional AC power sources.